The rate at which parks, golf courses and other open areas are being affected by animal litter is increasing to the point of being of great concern. For example, there are approximately 300 million geese in North America alone. Each goose discharges 3-4 times per hour resulting in approximately 3-5 pounds of waste each day and obviously a good part of this finds itself on recreational turf. In addition, the proliferation of dogs compounds this problem. Turf or grass becomes littered not only with animal waste but also dead leaves, aeration plugs, cigarette butts, lid cups, straws, syringes, lighters, rocks, and garbage. The most difficult litter to deal with is animal waste and aeration plugs. For example, it is common for geese to congregate around ponds, which are commonly found on golf courses and parks. A large number of goose deposits are invariably found at such sites. Such deposits make it unpleasant for the users of such sites who will generally look for alternative venues for their activities.
Various sweeping machines have been developed over the years to deal with litter. Most such machines have a rotary brush, which sweeps debris and waste into a rearwardly positioned hopper. Some early sweepers were operated manually such as U.S. Pat. No. 3,947,912 issued to Michaels, the rotary brush of which is driven by ground contacting wheels when the vehicle is moved. U.S. Pat. No. 4,608,725 issued to Jackson describes a rotary drum with fingers that rotates against a counter rotating spring finger assembly to aid in the pickup of material from the drum. This material is deposited onto a conveyer, which directs the material into a hopper.
U.S. Pat. No. 4,914,774 issued to Sheehan, et al. discloses a leaf-loading machine designed to be towed behind a towing vehicle.
U.S. Pat. No. 5,390,387 issued to Dube, et al. discloses a wheeled self-propelled vehicle that has a forwardly mounted engine, a hopper and a brush mounted on the hopper. The hopper and rotary brush are lifted by pistons affixed to the frame. Dube further discloses a paddle wheeled type of rotary brush powered by a hydraulic motor, with the brush being mounted at the entrance to a pivotal hopper. The hopper can be lifted and tilted to empty the contents thereof into another vehicle but only with the aid of hydraulic piston cylinders. The rear wheel of Dube is pivotal in either direction while the front wheels are unidirectional. Some vertical adjustment of the brush relative to the frame is possible through the insertion or removal of spacers on resting feet. No adjustment of the brush relative to the hopper is provided for. The brush can be operated in either direction of rotation depending on the setting of a control lever. However, rotating the brush towards the back of the machine would cause excessive scattering of debris because of the lack of a skirt around the back of the entrance to the hopper.
None of the foregoing patents disclose a convenient system for adjusting the height of the brush relative to the turf. Such an adjustment is desirable as the optimum height of the brush varies with the type and condition of the turf.